On 21 December 1988 a Pan Am 747 jet exploded over the small Scottish town of Lockerbie. On the 25th anniversary of the worst terrorist attack on British soil, this is the story.On 21 December 1988 a Pan Am 747 jet exploded over the small Scottish town of Lockerbie. On the 25th anniversary of the worst terrorist attack on British soil, this is the story.On 21 December 1988 a Pan Am 747 jet exploded over the small Scottish town of Lockerbie. On the 25th anniversary of the worst terrorist attack on British soil, this is the story.